Double operation forming die



Aug. 12, 1958 v L. HARDMAN DOUBLE OPERATION FORMING DIE Filed June '7. 1954 2 Sheets-Sheet 2 INVENTOR. LEON HARD M AN United States Patent Oflice &847,05 2 Ptented Aug. 12, 1958 2.847,052 DoUBLE-oPERAraoN-.FORMNG nm.v Leon' I-I'aifidinan, Wantag'h, N. Y. Application June 7.1954, serial Na. 434,763

(opisa- 21) Thisf invention relates .,to metal forming diesl andv more particularlystofisuc dies-.adapted-to perform double operations;on.E sheet. metak: forv forming botht Acmetype andY Pittsburgh Ztypesheet metal locks.

In .the shqet-metalindustry, fo'r instance in connection wth'ducts, forf air conditioning: and heating purposes,- lasrge sheets of: metal mustbe formed to fabricate the ducts.- Since these? ducts; are often large,` they are generallyformed., inhportions that ve anfbe packed flat for easy.warehousinggndtransportation. The ducts* are then' assemibledf looking the side portions with prefabricated locking portions. The present invention provides means for forming these-lockiiigmieges..

One of the problems in this industry is due to the fact that long sections, for instaiice;'8"t`o -feet long, are prefabricated. Therefore, the formingl dies must be equallyfasvlong, 8, 12 or` more feet;` These dies being so large require tremepdously heavy presses.

Many of the duet members, especially the looking means require: two or. more operations. t'o: perform them properly. For; instance, in theylocking member, therel is generally; a-.first .formingjandthen a-Lsqueezing operation. These operations could be formed in a conventional manner on separate dies. However, this would require separate handling and separate set-ups and would tie up two presses, which are very large and very expensive machines, as well as requiring handling and storage between operations.

Handling and storage are very serious problems due to the size of the pieces involved. For instance, to handle a piece of sheet metal six feet long takes at least two men. The present invention provides a die which performs two operations on the same press and die, thereby eliminating the need for a second set-up or press and eliminating all handling and storage between operations.

In one embodiment of the present invention the die has two portions, a front and an aft portion. The sheet metal is inserted from the front and under the aft portion and the first operation is performed by the aft portion, which for instance, is a forming operation. The metal is then withdrawn towards the front and a second operation, for instance a closing or hammering operation is performed on the next stroke of the press. The die is designed so that the front portion of the press does not interfere with the metal during the first operation performed by the aft portion.

The dies of the present invention are capable of forming both Pittsburgh and Acme type locks for sheet metal. These are well known locks in the sheet metal industry.

Accordingly, a principal object of the invention is to provide new and improved double operation forming the die means.

Another object of the invention is to provide new and improved means for performing two operations on sheet metal with the same die.

Another object of the invention is to provide new and improved metal forming die means which are simple and economical intv operation andwhich eliminate separate set-ups4 and` storage and handlingV problems between operations.

Another object of the present invention is to provide new-andlimproved die means for forming bothvPittsburgh' and Acme-type'locks in sheet metal.

Thesev and other objects of the invention will be apparent from the followingV description of drawings of which:

Figure l is an elevation sectional view of anfembodiment ofi-the invention illustrating first and second operations on a Pittsburgh type' lock. Figures 1A and-\1B show a Pittsburghflock.

Figure 2 is an elevation sectional view of anotheri embodiment illustrating. afsecond typelocking operation forming an. Acme type lock;

Figures 31 and 3A are elevationV sectional views. illustrating an Acrnertype lock;

Figure. 4 is' anhelevationview of another embodiment of the invention utilizing'a'spring loaded portion.

Referring to Figure 1, therezis shown a die comprisnglower die member 1, and upper die member 2. The upper die-member is. adaptedlto movevertically with respectlto the-lower. die' member ina press, which is not shown. The lfront'of the die is'to the right. This particular embodiment of the inventionM is` designed to performi two operations. The firstisa formingV operation and the. second*V is' a' closingoperation which` squeezes theV formed'porti'on` so'that the metal describes a loop vwhich nestsiin an' offset.` The sheet vto be locked is insertediinside the 180 bend'andV will'be in the same planeias :the first sheet, to formia- Pittsburgh type corner. lockzasshown-at D, Figure-1B.

The aftiportionof; the-lower die'comprises a positive memberx, whichf'is adaptedtobe inserted in a recess 4,

inv the: upper member.` Justito` the. left of the positive member.i.3 of` the-lower'die member 1 is a V shaped depression. The upper die member has a V projection 5' which is adapted to be inserted in the lower portion 5. The right. or front portions of the die are designed so as not to interfere with the sheet Which the first operation is being performed. Therefore, the sheet may extend out the front of the die any distance.

The operation of the die is as follows:

A flat sheet of metal is inserted from the front or right hand side to the rear of the die, against a suitable stop 15 incorporated in the die.

The die is then squeezed together and forms the metal piece A in the form as shown in Figure 1. When the die is opened the metal piece A is retracted to the position B. On the next stroke of the press the formed or crimped metal sheet B will be squeezed flat between the upper and lower die faces. A spacer 13 is attached to the lower die face to provide a space 13', Figure 1A, in the finished product C. The spacer permits easier insertion of the sheet metal 16 Which is to be locked to the piece D the locking portion. The end 17 is then hammered over when being installed to form the corner lock, as shown in Figure 1B.

In using the present die the metal sheet may be inserted by one man from the front for the first operation then retracted slightly for the second operation and then removed thereby eliminating all handling and storage between operations. Therefore, the embodiment of Figure 1 shows means for forming a Pittsburgh type sheet metal lock with one die performing two separate operations in a minimum of tirne and with a minimum of handling.

A, B and C show the successive forms taken by the metal blank and the form D shows the piece 16 of the member to be locked inserted in the Pittsburgh lock D. This insertion is generally performed in the field on the 3 job and then the left hand edge 17 of the lock is then hammered over.

Figure 2 shows another embodiment of the nvention which is adapted to form the Pittsburgh type lock in exactly the same fashion as described in connection with Figure l and which also may be used to form an Acme type lock. In this modification, the die face slopes downwardly at a slight angle towards the front or right hand side. The members A', B', C' and D' illustrate the formation of the Acme type lock. In forming the Acme type lock, a stop, which is the pin 20, is inserted in a hole 21 in the lower die 1. A hole 22 adapted to receive pin 20 must be inserted in the upper die 2. This pin 20 will be removed, of course, when it is designed to form a Pittsburgh type lock.

The operation of forming the Acme type lock is as follows:

A flat metal blank A' is rested on the lower die in a substantially horizontal position and held against the stop 20. The first stroke of the press will form the piece B' which is then retracted by the operator and then held in the position C', in notch 19. The next stroke of the press will turn over and squeeze the hook of the member C' to form the complete locking member D'.

Figures Sa and Sb show the formation of a complete Acme lock in the field. The two pieces D' are hooked together as shown in Figure 3a and then hammered flat as shown in Figure 3b.

Figure 4 shows another embodiment of the nvention utilizing a spring loaded projecting member 30 in the upper die 32. The lower die 31 is substantially the same as shown in Figure 2 except it slopes down to the front. One of the primary problems in these dies is that the first contact with the metal blank should be made at the point 33 and not at the point 34. When the first contact is made at point 34 the metal blank is liable to be twisted and turned in the operator's hands. The embodiment of Figure 4 is specifically designed so that the first contact will be made at the point 33 and in addition due to the 4 spring loading of the member 30 by the spring 40, this impact will be automatically compensated so that it will not be so great as to shift the position of the metal piece which is being formed. Otherwise the operation of the embodiment of Figure 4 is the same as that of Figures l and 2.

I claim:

A double operation sheet metal die for performing successve forming and squeezing operations on the same portion of a metal sheet comprising an integral lower member having a first V-shaped recessed portion in the top plane thereof spaced from a first side of said lower member, a second recessed portion spaced from said first recessed portion, said second recessed portion comprising first and second step portions from said top plane, a spacer mounted on said first step portion and extending over said second step portion, a first stop afiixed to said first side of said lower member, an upper member having a first V-shaped projecting member positioned to mate with said first recessed portion of said'lower member, said upper member having a second projectng member positioned to mate with said spacer, said V-shaped means being arranged to form a V-bend in a metal sheet during a first mating of said dies and said spacer cooperating with said second step portion of said lower member and said second projccting portion of said upper member to form said V-bend into a U shape of predetermined spacing around said spacer during a second mating of said dies.

References Cited in the file of this patent UNITED STATES PATENTS 1,813,520 White July 7, 1931 2,504,782 Allen Apr. 18, 1950 FOREIGN PATENTS 7,533 Germany Oct. 14, 1879 140,016 Great Britain Mar. 18, 1920 483,378 Canada May 20, 1952 

